Linux 5.17 AArch64 Code Has SME Preparations, Adds KCSAN Support
Linux 5.17's 64-bit ARM code has a few feature items at play and a lot of code cleaning / preparations for future kernel cycles. This pull is just about the architecture work and not the Arm platform/DT updates for new SoC and hardware support, which will be sent separately as a PR during the merge window. The ARM64 updates for Linux 5.17 include:
- The Kernel Concurrency Sanitizer (KCSAN) is now enabled for ARM64. KCSAN is a race detector for the Linux kernel relying on GCC and Clang compiler instrumentation. KCSAN has already been supported on other architectures while 64-bit ARM is now part of the supported list.
- Clean-ups and preparations towards pringing Scalable Matrix Extensions (SME) to the kernel albeit not for Linux 5.17. Armv9-A's Scalable Matrix Extensions build on SVE/SVE2 for providing better and faster support around matrix operations. SME allows for matrix tile storage, load/store/insert/extract tile vectors, outer products of SVE vectors, a streaming SVE mode, and other improvements.
- Usage of SHA3 instructions for speeding up XOR.
- Perf subsystem updates for more Arm PMUs.
- Code clean-ups around atomics, BTI (Branch Target Identification), and other work.
- Various other code fixes and improvements.
See the ARM64 updates for the full list of arch changes for this next kernel cycle.